Filter
Top Products
FX Series Programmable Controllers Devices in Detail 4
4-6
4.4 State Relays
Device Mnemonic: S
Purpose: Internal programmable controller status flag
Alias: State (coil/ relay/ contact/ flag)
S (coil/ relay/ contact /flag)
STL step (coil/ relay/ contact /flag)
Annunciator flag
Available forms: NO (➀ ) and NC contacts and output coils (➁ )
(see example device usage for references)
Devices numbered in: Decimal, i.e. S0 to S9, S10 to S19
Further uses: General stable state - state relays - see page 4-6
Battery backed/ latched state relays - see page 4-7
STL step relays - see page 4-8
Annunciator flags - see page 4-9
Example device usage:
4.4.1 General Stable State - State Relays
A number of state relays are used in the PLC. The coils of these relays are driven by device
contacts in the PLC in the same manner that the output relays are driven in the program.
All state relays have a number of electronic NO and NC contacts which can be used by the
PLC as required. Note that these contacts cannot directly drive an external load. Only output
relays can be used to do this.
X0
X1
1
S20
2
S20
Available devices:
• Please see the information point on page 4-7 ‘Battery backed/ latched state relays’,
or see the relevant tables for the selected PLC in chapter 8.